Introduction:
Welcome to Section 8. This game is an enjoyable First Person Shooter. You play as Alex Corde of the 8th Armord Infantry.
The achievements are rather easy, although 2-3 of them can be time consuming.
The campaign, which consists of eight objective-based missions, is relatively short, as it is more a tutorial to the multiplayer part of the game. The campaign itself will net you 160 and requires you to play on Hard difficulty. Although the game is multiplayer oriented, most of the achievements can be unlocked by playing offline/single player. The hardest part of the game is to find an online community to play with. As for steps numbers 2, 3 and 4, you might want to find people in the achievement trading thread found here.

Step 1: Campaign
In order to start the campaign, choose "Corde's Story" from the main menu. Be sure to set the difficulty to "Hard". All missions are pretty short and are more an introduction of what to expect on multiplayer. None of the missions are difficult except for one maybe, which is the map Edge of Oasis. If you get stuck on a mission, you might want to check the achievement discussion thread found here and hopefully you'll find the answer based upon other people's experiences.

As soon as you've finished the first mission, you'll unlock the First Drop achievement. Mid-way through the game, you'll also unlock the To the Delphi Man achievement. Throughout the game, you'll come across the Nuclear Dawn map where you can unlock the With All Due Haste achievement. On the Blackstone Marsh map where you can get the Lightning Assault achievement. Both achievements are to perform a specific action within a certain amount of time. The Lightning Assault achievement can be done on the easiest difficulty setting by chosing "Level Select" after you've beaten the game. But With All Due Haste has to be done on Hard difficulty. At the end of the campaign, you'll unlock both Mission Accomplished and Over Achiever achievements assuming you did it on Hard difficulty.
There are also a few achievements that need a little grinding, but we'll come to that in the next steps.

Step 2: Offline Non-campaign / Multiplayer (2+ human players and/or bots)
Now that you've done the campaign, it's time to focus on the other achievements that you can get offline, although it's better to boost them with another player in order to speed things up and make it easier to unlock them (LIVE Gold accounts required).

One basic rule, though, is to always set difficulty to "Trivial" to make it as easy as possible, unless the achievement requires otherwise.

Before you start with these, you have to know how to get a "Feat" as several "Feats" activate a DCM (Dynamic Combat Mission) which both will be important towards the Feats and Badges related achievements.
For information about Feats go here.
For information about the DCM go here.

If you had difficulties unlocking the Boom Goes the Dynamite achievement in Step 2, you might want to do it when playing in a game with 4 people or more. Note that if you need 3 people on the other side of the team to boost this specific achievement with, you either have to be in an 8/12/16 player game with bots active so that the human players can swap from one team to another, or you need to have 5 (or more) human players if you set the bots inactive.

Since not so many people have downloaded the DLC yet, boosting is best done on a DLC map (Azure Basin, Devil's Backbone or Hornet's Nest) so you don't get annoyed by people playing legit when boosting.

Seek and Destroy Map Pack

Single Player
If you're a god with shooters, you won't have any troubles unlocking the DLC achievements. Again, always set difficulty to "Trivial" unless achievement requires otherwise.
The achievements that can be done on "Trivial" are: Dance with the Devil / Buzz Kill / All Your Basin / Plow The Road / Revenge of the Falling / Army of One / Immortal Sovereign / Swarming Behavior
The achievements that have to be on a harder difficulty are: Insanity Defense / For the Swarm

Co-op
But since you're reading this step, maybe you're not such a god with shooters after all. It is best to do the Insanity Defense and For the Swarm achievements with a human player in co-op as the AI of the bots on your team won't be a big help to you, trust me! And while you're at it, Plow the Road, Immortal Sovereign and Swarming Behavior are also more fun with a real human assisting you.

Conclusion:
If you are a completionist, I hope the road map and guide have been helpful in order to get the full 1250. An achievement that you possibly haven't unlocked yet, would be the We Have Won which is a time consuming one and needs a little grinding. With a little research on the internet, you'll be able to find an easy way to unlock this one using rubber bands. Perhaps you're also missing the Feat and Badge Experts. Again, having a good team to play with, preferably on a DLC map, and understanding the DCM mechanics are the key ingredients to make this work faster.

Capture the Munitions Facility in Blackstone Marsh within 4 minutes of hacking the Heavy

This is the Seventh mission in the game. Once you hack the heavy, don't get into it. Run to the left side of the map and enter the munitions facility from the right hand side. Kill the few guys that come out of the door and capture the control point when it is clear. This can be done on any difficulty, easy is suggested. If you miss this on your first playthrough, just use the mission select feature.

Finish all 8 missions and this achievement will unlock. There are only 1 or 2 really hard sections to this game and it can be completed in about 6 hours on hard, sometimes less. If you are still having problems, check out this thread for a few tips on the harder spots.

You can either boost it with a friend or do it legit. If you boost it, just drop to a part of the map where no one is around and keep killing your friend. If you want it legit, just keep hacking and capturing control points (3 points for a hack, 10 for a capture). Get as many kills as you can and complete other side objectives as you can.

There are 32 badges total in the game, and they all need to be achieved in ranked matches. Remember you need at least 4 people in a match be able to achieve badges and experience. You can view your badges under dropship from the main menu, then awards. You can boost these in a ranked match as well, just invite a friend to your ranked match. Here's a spreadsheet by Wulfaur to keep track of which ones you need.

Start a private match and change the mode to 'Swarm', the difficulty to 'Trivial' and players to 8. This will be a VERY easy game. Just control all of the Control points until your team reaches 1000 score.

Start a private match and change the mode to 'Super Swarm', the difficulty to 'Trivial' and players to 8. The only difference between swarm and super swarm is you only have 1 CPU team mate in this mode. But same as before, just capture the Control points to win.

You'll need 14,500 XP to hit level 50 and should unlock when you get the correct amount of XP, not at the end of the match. If at anytime you loose your rank, just play a few games and rank up to level 5. From there, you should get all of your rank back one after another.

Just win a ranked match. You need to be in the game for more than half of the round. It's very easy to win a match, just complete as many of the objectives as you can. This will probably be one of the first online achievements you will get.

Easily done boosting with 4 other people in a private match. Just meet up and use the remote charges (select them with , us to throw them and to detonate them). You need 3 people on one team and 2 on the other then swap back and forth until everyone has the achievement. If you want to do it legit, trying planting remote charges all over a control point and detonate them when 3 enemies are close to it. It's much harder than it sounds though.

Kill 5 players in a row with only Grenades and Knives in a ranked match

Best way to get this is boosting. Just land on a empty part of the map and kill the other player with grenades or a knife. You switch secondary weapons with the button and use them with . You can select these weapons in the loadout screen.

This can be boosted or done legit, but must be in ranked matches. You can check your progress in the dropship option from the main menu. This will unlock as soon as you get the 100th kill, not at the end of the match.

These can be done in ranked or private matches. You can destroy a tank or heavy Armour vehicle easily by dropping 5 remote mine on them and detonating them at the same time. Rockets also work very well.

Probably easier to boost this one than get it legit. Just select a spot to drop your deployable and as soon as the marker is dropped, get your friend to stand over it. You many need to look up and see when it is as it drops because sometimes they drop a bit to the left or right of your marker. The deployable will kill the player and net you the achievement.

This can be done in ranked or private matches. Just destroy everything at one of the bases (AA turret, missile launcher, etc) before capturing it. It must be captured by the opposing team first, IE: you can not do this at the beginning of a match while the base is still neutral.

Get as close as you can to an enemy control point and deploy a sensory array. A good place would be somewhere out of sight, like on top of a building or behind some crates. As soon as your sensor lands, the achievement will unlock.

This will probably be the most time consuming achievement in the game. Just keep running everywhere you go and all of the km's will pile up. This is accumulative between ranked and private matches. You can check your progress in the dropship option from the main menu, then select achievements.

As the description says, you must win a ranked match in under 14 minutes. This is going to be hard as most matches go between 16-20 minutes. Try to capture the Control points as quick as possible and lay as many deployable as you can around the area to keep the opposing team out. Team work will be a must. Remember that finishing DCM's will add to your score, so try and complete those ASAP.

Just change between your loadouts 3 times. You can do this before you drop at the dropship menu. You can use your custom loadouts or the defaults one's in the menu. This will unlock after you pick your 3rd selection.

Invite 10 players into your squad (and have them accept) in multiplayer

This can be done in private or ranked matches. Each team (section 8 or arm of orion) has 6 squads (Alpha, beta, gamma, etc) You can join any squad under 'squad management' from the dropship menu in game. Next, make sure one of your friends is on your team and invite the to your squad by clicking on your squad twice, then click Invite friend and select your friend from the list. You can kick the player and re-invite them 10 times until the achievement unlocks. If you don't have anyone to invite, you can also do this with bots, but only in instant action.

This one can be hard. Remember you need to capture your control point, not just hack it. I would recommend trying this on a smaller map with few players. Stick around your first CP until it is captured then run over to another one and try to capture that one. this may take a few tries, but if you have some friends that will keep the other team away from you, then even better.

Just complete 100 repairs in the game. You select the repair tool in you loadout menu and select it by pressing in game, it's a wrench icon. The use to repair a broken object or heal a team mate. You can only use it for so long before it it needs to recharge. You can check your progress with dropship option in the main menu, then select achievements.

Concentrate on hacking and capturing control points as best as you can, just don't kill any players. You can destroy turrets, but remember you need at least 4 players in the match for your stats to count. as long as you get 30 points, the achievement will unlock at the end of the match.

Once you can break when you are dropping, push the button and you'll be able to move around. Try your best to land on another player, which will kill them instantly. This is much easier boosted with a second player. Much like dropping your supply's on them, just get them to stand in one spot and land on them. This can be done in ranked or private matches.

Can be done solo (Instant Action) or in multiplayer (Ranked or Private match)

If you do it in a Private Match with a friend, then have your friend Free Spawn in front of you after you are deployed. Stand beside your friend and run away from him and from the moment you go into overdrive mode, stop running and turn around and shoot your friend until he is one shot away from dying. Now run at him. You should hit the overdrive mode a few feet before you get to him and you will kill him instantly. Rinse and repeat 4 more times and the achievement will pop.

You can also do this with bots, but it may be somewhat harder. If you do attempt it with bots, remember that as long as you are running then it will hurt them, so if you miss the first time, do a U-turn and keep trying to hit him. Can only be done on enemy bots. Enemy bots on Trivial difficulty take about 2 hits to get killed by colliding into them in overdrive.

Can be done solo (Instant Action) or in multiplayer (Ranked or Private match)

An easy way to get this achievement, is to burn in using the Infiltrator loadout since this loadout is pretty resistent to air attacks while burning in, especially on an easy difficulty setting.
So, set game difficulty to "Trivial", combat mode to "No bots" and pick any map you like. Just make sure to burn in on a base that has only one turret and not two, as two turrets can kill you.

Choose "Free Spawn" and set your drop zone (crosshair) on an AA-turret, and start burning in. When the game tells to press to brake, DON'T! Just crash onto it!
You might be lucky and destroy the AA-turret on the 1st try. If you don't, equip your shotgun (which is the 2nd weapon with the Infiltrator loadout, so press to switch weapons) and shoot at the AA-turret until it's almost one or two shots away from being destroyed.

You will notice one (maybe two) repair drone(s) flying around the AA-turret to repair it. Destroy these repair drones.

Now, press and press or until you're on the "Dropship" tab. From the list, choose "Self Destruct".

Time to repeat the 1st step and burn in again on the AA-turret. Move the crosshair slightly if you noticed you've crashed next to the AA-turret on the 1st drop. Again, don't press when prompted.

Keep repeating these steps until you crash & destroy the turret, and the achievement unlocks immediately.

You can play however you feel comfortable with, as long as combat mode is set to "One Man Army" and you have to win the game or course. From the main menu, choose Instant Action. Easiest settings are the same as usual:

Map: pick any you like

Mode: MUST be "One Man Army"

Difficulty: Trivial

Players: 8

In regards to the glitchy part, I used above settings on the Nuclear Dawn map, won the game but the achievement didn't unlock.
Used the same settings over again but this time on the Edge of Oasis map, and got the achievement.

Can be done solo (Instant Action) or in multiplayer (Ranked or Private match)

Alright, this one can be a real pain if you're doing this one solo. It's better to have a friend helping you with this, since it'll make it way easier. If your friends don't have Section 8 or simply aren't online, and you don't want to do it on your own, you might be able to find someone in this thread to help you.

But in case you want to try it by yourself, following strategy might be helpful...

First, start Instant Action from the main menu using these settings:

Map: Orbital Relay West

Mode: Super Swarm

Difficulty: Insane

Players: 8

Choose whatever loadout you like to play with. I use the Infiltrator loadout but equiped with the Assault Rifle as primary and Rocket Launcher as secondary weapon. I also equiped the Repair Tool and Det Packs.

Now, set drop zone to control point number 2 and start burning in. The AA-turret will lower your shields but not kill you. Once arrived, start hacking the control point (CP) and put all 5 Det Packs on the CP and get the hell out of there.
The enemies will swarm the CP and once they are close enough, it's time to press to detonate the Det Packs and kill some of them.

Don't bother capturing CP2 over again (nor CP3). Instead, it's time to focus on killing as many and as quickly enemies as you can, as it will add to your score but more important you'll get money. If you're not skilled in killing enemy bots, use your Rocket Launcher to destroy assets instead. It takes approx.2 rockets to destroy Minigun Turrets, Array Sensors and Supply Depots and it takes approx. 4 rockets to destroy an AA-turret.

Once you have enough money (60$ or more), go back to CP2 and kill the enemies. CP2 is important as it is the only of the two control points that can be accessed by air transports. You'll understand why in a moment...When clear of enemies, start to hack CP2. Once hacked, deploy 1 Supply Depot and 1 Minigun Turret as close as possible to CP2. Once deployed, the Minigun Turret will start killing enemies as they enter the base, giving you score points and money. When they are trying to destroy the Minigun Turret, the Supply Depot will start repairing it if deployed close enough.

As soon as you have another 60-100$, deploy 1 more Supply Depot and 1 (preferably 2) more Minigun Turret(s)s as close as you can to the first set-up. This is tactically an important part of the battle: enemies trying to enter the base will suffer from heavy fire from the Minigun Turrets. If they are trying to destroy the Supply Depots, the Supply Depots start repairing eachother. And, for every 3 repairs you get one Support Feat (we'll come to that in a moment). Last but not least, it will also guarantee that CP2 won't be easily captured over again by the enemy and you get points every now and then for each CP captured. If the enemy succeeds in destroying one or more deployables, you should have enough money by now to set the same deployables back active.

Now you can focus on the DCM that are and/or will become active. More information about the DCM can be found here. You're main objective should become now: 1) be victorious on the DCM that become available to you, and 2) make the enemy fail the DCM that becomes available to them. Being victorious on your DCM will give you score points, and none for the enemy. Making the enemy fail their DCM, will increase your score and not theirs. Don't bother killing enemies (unless necessary to get the DCM done) or capturing control points.

As stated earlier, you get 1 Support Feat for every 3 repairs, and you'll need several Support Feats to activate the Convoy DCM. To find out what it'll cost you (costs vary sometimes!) to activate a DCM, press and go with the or on the "DCMs" tab. More information on how to get Feats can be found here.

The Convoy DCM will become active quite easily because of the repairs going on between the Supply Depots and the Minigun Turrets. And, your kills with the Assault Rifle will contribute to activate the Outpost DCM which is 100 points for each victory!
The Convoy DCM is important as it is a heavy armored (but slow) vehicle, and has some powerful weapons on board as well. Very helpful against the enemy's Commando and VIP DCMs!! And remember, if your Convoy needs to be repaired, go as close as you can to the Supply Depot in CP2.

If the enemy activates the Intel DCM that you have to pickup, don't bother. It'll be located high on the huge satellite dish and there will be 4-6 enemies, which means getting killed quickly. Instead, go capture their CP for fun.

If the enemy activates the Bomb DCM, go with your Convoy to your base. They'll probably won't make it there, because of the 3 Minigun Turrets you put in place killing the enemy as soon as they try to enter your base. This will give you 35 points for them failing.

Good luck!

This achievement will also contribute to the Swarming Behavior achievement.

Loadout: Guardian but equiped it with Assault Rifle as weapon 1 and Rocket Launcher as weapon 2. I also had the Repair Tool and the Det Packs.

I focussed mainly on hacking and capturing check points. The few bots that came to me trying to capture the control point were easy kills with the assault rifle since it was on trivial difficulty.
As soon as the DCM (Dynamic Combat Mission) became active, I focussed on doing those to increase the score quickly. If you have to do a DCM but there are too many enemies involved, stay away from it. Let your friendly bots do the job, and focus on another DCM if active, or otherwise capture control points if any available, or kill enemies one by one.
When hurt, heal using the repair tool!

Can be done solo (Instant Action) or in multiplayer (Ranked or Private match)

In order to unlock this achievement, you'll have to win on the maps from the main game and the DLC as well. Winning on the DLC maps will also give you the All Your Basin, Buzz Kill and Dance with the Devil achievements. Be sure to set difficulty to "Trivial" to make it easier for yourself. The maps are:

Can be done solo (Instant Action) or in multiplayer (Ranked or Private match)

Similar to the Swarming Behavior achievement, except combat mode has to be set to "Swarm" and difficulty to "Hard". I suggest doing this with a friend, as the AI of your friendly bots won't be a big help. Again, you have to win on all 11 maps.